In the late 1800s and early 1900s, carbonated beverages such as Coca-Cola, Dr Pepper and 7UP were sold as nerve tonics and health drinks. But, we now know that sugary sodas contribute to obesity, type-2 diabetes and cavities. Still, most Americans drink more soda than they like to admit.

Even though sugar-laden soft drinks have no nutritional value, they are still eligible for food stamps. Nutrition researchers and some politicians have advocated for a ban on buying sugar-sweetened drinks with food stamps but the U.S. Department of Agriculture, which runs the program, is under tremendous pressure from beverage company lobbyists to keep the existing regulations.

Sugary drinks are especially concerning because too many liquid calories put consumers at a higher risk of developing type-2 diabetes. Some nutrition experts are concerned that taxpayers are subsidizing an unhealthy diet, which will result in higher medical costs for Medicare and Medicaid down the road, when food stamp recipients experience the health problems associated with obesity and diabetes.

In a new study (subscription required) published in this month’s Health Affairs, Sanjay Basu, MD, PhD, an assistant professor of medicine at the Stanford Prevention Research Center, and his colleagues created a computer model to simulate the effects of a soda ban on the health of food stamp recipients. They found that obesity would drop by 1.12 percent for adults, and by 0.41 percent for children, affecting about 281,000 adults and 141,000 children. Type-2 diabetes would also drop by 2.3 percent.

The researchers also calculated the effects of reimbursing participants 30-cents for each dollar spent on fruits and vegetables. The subsidy did not affect obesity or diabetes rates, but doubled the number of people who ate the recommended number of fruits and vegetables each day. A county in Massachusetts tried the same reimbursement system as part of the USDA’s Healthy Incentives pilot study, and saw a similar increase in the fruit and vegetable purchases of food stamp recipients.

“It’s really hard to get people to eat their broccoli,” said Basu in a press release. “You have to make it really cheap, and even then, sometimes people don’t know what to do with it.” But, with one in seven Americans receiving food stamps, he points out that these small changes can have wide-ranging effects.

“It’s very rare that we can reach that many people with one policy change and just one program.”

Patricia Waldron is a science writing intern in the medical school’s Office of Communication & Public Affairs.